The Transmission Control Protocol (TCP) is a core transport-layer protocol designed to provide reliable, ordered, and error-checked end-to-end delivery of data between networked applications. Operating on top of the best-effort Internet Protocol (IP), TCP guarantees data integrity by numbering individual data units, tracking acknowledgments from the receiver, retransmitting unacknowledged or lost data, and adjusting transmission rates to manage network congestion.

Transmission Control Protocol (TCP)

The TCP three-way handshake is an ordered connection-establishment procedure performed before any application data is transmitted. It consists of three sequential steps:
1. The initiating client transmits a SYN (synchronize) packet to request opening a connection.
2. The recipient server responds with a SYN-ACK packet to acknowledge the request and signal consent.
3. The client sends a final ACK packet back to the server, establishing the bidirectional connection.

While this preliminary handshake ensures synchronized and reliable communications, it introduces a slight startup delay compared to connectionless protocols.

TCP Three-Way Handshake

TCP maintains reliability during data transfer through sequence tracking, packet retransmission, and congestion control:
- Because TCP assigns sequential numbers to each outgoing packet, the destination device can immediately detect gaps in the received sequence.
- When a packet is lost, no acknowledgment is returned to the sender, signaling packet loss and prompting the sender to retransmit only the missing packet.
- When packet loss occurs as a result of network congestion, TCP automatically reduces its transmission rate to alleviate traffic load, gradually accelerating back up as network conditions improve.

TCP Packet Recovery and Congestion Control

The Internet Protocol (IP) is a core network protocol responsible for addressing and routing data packets from a source device to a destination device across multiple interconnected networks using IP addresses.

Internet Protocol (IP)

University of Michigan - Ann Arbor

Ch.3 Core Internet Protocols - The Architecture of Connected Systems: Tracing End-to-End Data Flow @ University of Michigan - Ann Arbor

Internet Protocol (IP) - The Architecture of Connected Systems: Tracing End-to-End Data Flow @ University of Michigan - Ann Arbor

Transmission Control Protocol (TCP) and the Three-Way Handshake - The Architecture of Connected Systems: Tracing End-to-End Data Flow @ University of Michigan - Ann Arbor

Learn Before

Related

Learn After